H. Mijail's Blog

2017-08-29

After a few weeks using CrashPlan PRO for small business (not the free tier!) I tried contacting support to ask how to do some underexplained things, and/or to open some bug reports/feature requests. Like:

How to know which were the last backed-up files? or, when was a file last backed up? (maybe some useless-but-frequently-updated file is slowing down backups of bigger and more important files?)

The app defines backup sets, but they don't seem to correspond to "restore sets". How to restore a particular set?

Support's answers were pretty underwhelming, bordering on canned-responses; but I found that Code42, the makers of CrashPlan, have an API to access the backup data. So I browsed a bit to see whether it'd be easy to do myself what I wanted.

2017-07-23

Living in Warsaw, I got tired of worrying about the air quality – which some days during winter got reported as worse than that of infamously polluted Beijing. So some months ago I bought an air purifier.

I had a number of doubts about how to use it so it was effective: does it have to work all day? The purifier's power level depends on the room's size, how do I know that it's working as it should? Air quality sensors included in these purifiers are said to be pretty unreliable, are they any useful at all? How does air quality indoors correlate to air quality reported by an official station about 1 km away from home – which daily recommended wearing a mask during winter!? What happens if I just leave the windows closed, or if I open them for a while? ...

So I bit the bullet and bought an air quality sensor, which cost almost as much as the purifier itself.
And these are my results and tips for anyone thinking about doing the same.

2017-06-16

Python makes it apparently easy to install packages. Just use pip, or any of the other more-or-less old and deprecated ways to install them, right? (heh)

The first difficulty is that maybe your system's Python needs sudo to install those packages, and you don't want (or even can't) use it.

The definitive solution is to use virtual environments, but that can feel like going too far in the "local" direction. You might just want to have something at the user level, without having the risks of using sudo, but still global for everything that the user does.

Well, turns out that PEP 370 allows you to have user-local installs of packages. You're supposed to run pip --user install whatever.

But now you have to remember to always use the --user flag! Kinda breaks the purpose of having something "global for everything that the user does".

(Note to self: "lightness" in Linux rather correlates to "barebones" [3],
which correlates with "hardcore" (text configs, mailing list scouring,
lots of googling). Next time I'll be trying a heavy-weight distro for
this kind of thing; better slow-but-useable than less-slow-but-WTF.)

2016-08-27

(Sometimes after a couple of hours of research, the result is a dead-end or needs further digesting. Still, such a result might itself still be worth remembering. This is a Quick&Dirty report of one of those cases.)

GCD is an implementation of thread pools / queueing (+ event management (sockets, files), etc) by Apple for Mac OS X / iOS. It was open-sourced, and FreeBSD got an implementation. They are practically an abstraction and simplification over pthreads (+ events, etc), and the GCD implementation includes some kernel and compiler changes (workqueues and blocks, respectively). Implementation details at http://newosxbook.com/articles/GCD.html. It's well performing and seemingly can help simplifying a lot.

What if one wanted to use GCD in Android? Is there anything compatible enough and that could be used at the C level?